Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.
The same repeated number may be chosen from candidates unlimited number of times.
Note:
All numbers (including target) will be positive integers.
The solution set must not contain duplicate combinations.
Example 1:
Input: candidates = [2,3,6,7], target = 7,
A solution set is:
[
[7],
[2,2,3]
]
Example 2:
Input: candidates = [2,3,5], target = 8,
A solution set is:
[
[2,2,2,2],
[2,3,3],
[3,5]
]
AC代码
void digui(vector<int>& candidates, int target, int idx, int sum, vector<int>& v, vector<vector<int>>& ans) {
if (target == sum) {
ans.push_back(v);
return;
}
else if (target < sum) return;
else {
for (int i = idx; i < candidates.size(); ++i) {
v.push_back(candidates[i]);
digui(candidates, target, i, sum + candidates[i], v, ans);
v.pop_back();
}
}
}
class Solution {
public:
vector<vector<int>> combinationSum(vector<int>& candidates, int target) {
sort(candidates.begin(), candidates.end());
vector<vector<int>> ans;
vector<int> v;
digui(candidates, target, 0, 0, v, ans);
return ans;
}
};
总结
应该算是深度优先搜索
